OK, here are a couple more questions. Everything is setup in my sump and running. My skimmer is not producing any bubbles inside the main canister. I am confused about the whole refugium concept. I am feeding water into my refugium via a tee off the return pump. But how does the filtration that the refugium provides get into the main tank? Am I to have a pump going from refugium into main tank? Does the water just rise over the divider, feed into the return pump area and that is how the main tank gets the advantage of the filtration the refugium provides?